Summary assessment enables expedited tax assessment to protect revenue, with deeming of the person in charge as taxable where necessary. Summary assessment allows a proper officer, with prior permission of the Additional Commissioner or Joint Commissioner, to issue an expedited assessment order when evidence of tax liability suggests delay would prejudice revenue; where the taxable person is unascertainable for goods, the person in charge is deemed the taxable person and liable; the Additional Commissioner or Joint Commissioner may withdraw an erroneous summary order on application or on their motion and require follow-up under regular reassessment procedures.